Mobile communication devices, such as mobile phones or personal digital assistants (PDAs), are today used for many different purposes.
Most commonly such mobile communication devices have access only to one type of network. A typical case is mobile phones only having access to a mobile communications network of the Global System for Mobile communications (GSM) type. As is commonly known the GSM system is a typical example of a cellular network, said network comprising a plurality of covering cells served by base stations, which base stations facilitate the communication between the mobile communication device and the network. As the mobile communication device moves from one geographical location to another it will move from the covering cell of a first base station to the covering cell of a second base station. The process of handling the communication switch of the mobile communication device from the first base station to the second base station is called a handover.
Moreover, during recent years different types of wireless wide area as well as local area networks have been developed and deployed. Examples of wireless local area networks include wireless Voice over IP (VoIP, Voice over Internet Protocol) networks, WiMAX (Worldwide Interoperability for Microwave Access) networks, etc. Typically the wireless local area networks comprises covering cells served by so-called access points.
Mobile communication devices with functionalities for both wireless wide area networks, such as GSM, and wireless local area networks, such as wireless VoIP networks, have been introduced. However there is still a problem with handover from wireless networks of different types. This type of handover is usually referred to as a vertical handover.
WO2005071998 discloses a method for performing a vertical handover of a wireless voice connection, wherein the decision for performing the handover is based on a set of handover factors. Hence WO2005071998 discloses a method for determining when such a vertical handover may be performed. However the problem of how to perform such a vertical handover in an efficient manner still remains. Typically, methods for vertical handovers cannot deploy known handover techniques which have been established for handovers within one single network, such as the above example regarding handovers in a GSM system. In view of the above, the invention seeks to solve or at least reduce the problems discussed above. In particular, the invention provides a method for handling a connection between a mobile communication device and a second communication device via a server.